HazMat Tool — substance information

Hexamethylene diisocyanate

HMT May 2026
UN / ID
UN 2281
Hazard class
6.1
Packing group
II
ERG guide
ERG 156
Special provisions
SP IB2, SP T7, SP TP2, SP TP13
Source
49 CFR §172 (2026/05)

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Hexamethylene diisocyanate


Hexamethylene diisocyanate (HDI) is the organic compound with the formula (CH2)6(NCO)2. It is classified as an diisocyanate. It is a colorless liquid. It has sometimes been called HMDI but this not usually done to avoid confusion with Hydrogenated MDI. Wikipedia

Substance Data

Source: PubChem (HSDB, 26.11.2019)

CAS-Number

822-06-0

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 156

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

6.1
Poisonous Material

(4) Identification number Help

UN 2281

(5) Packing Group Help

II

(6) Labels Help

Poisonous liquids PG I Zone A (6.1)

(7) Special Provisions (§172.102) Help

×Note:
Special provisions may be very complex. The extracts are taken from 49 CFR §172.102. Please be careful with the information, as necessary, additional conditions may be applied that are not written here. Please check the original source and report bugs.
IB2
T7
TP2
TP13

(8) Packing Authorizations (§173.***) Help

(8A) Exceptions153see 49 CFR §173.153
(8B) Non-bulk202see 49 CFR §173.202
(8C) Bulk243see 49 CFR §173.243

(9) Quantity Limits Help

(9A) Passenger aircraft/rail5 L
(9B) Cargo aircraft only60 L

(10) Vessel stowage Help

(10A) Location
(10B) Other

Segregation chart for load, transport, and storage

This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.

Scope & sources (important)Click to show CFR references

This check evaluates segregation per 49 CFR §177.848. Additional loading/unloading and handling requirements may still apply; see 49 CFR §177 Subpart B (Loading and Unloading):

  • §177.834 - General requirements
  • §177.835 - Class 1 materials
  • §177.837 - Class 3 materials
  • §177.838 - Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (pyroforic liquid) materials
  • §177.839 - Class 8 (corrosive) materials
  • §177.840 - Class 2 (gases) materials
  • §177.841 - Division 6.1 and Division 2.3 materials
  • §177.842 - Class 7 (radioactive) material
  • §177.843 - Contamination of vehicles